Machine for making mechanical drawings



M y 6, 1952 A. A. GOERZ 2,595,842

MACHINE FOR MAKING MECHANICAL DRAWINGS Filed Oct. 1. 1946 -9-illlllllllli yf mmnu l6 G/NVENTOR A 7' TORNE 7" Patented May 6, 1952UNITED STATES PATENT OFFICE MACHINE FOR MAKING MECHANICAL DRAWINGS 8Claims. 1

This invention relates to a machine for making mechanical drawings.

Stated more specifically, the invention pertains to a detached orportable drafting machine which, when placed on a drafting board willmake drawings and measure drawings without the use upon the board offixed attachments or extraneous guides.

Accordingly it is an object of the invention to provide aself-contained, detached drafting machine which has incorporated intoits structure improved means for accurately determining its movementsacross a drafting board in various directions having predeterminedangular relations.

Among other objects are: to provide improved means for adjustablymounting straightedges; to provide an improved combination of brake andbrake release means for roller means movable across the surface of theboard; to provide manually operable means for adjusting the surface orrolling contacts of pairs of wheels in relation to the surface of thedrafting board; to provide improved handle means for the accuratemovement of the machine across the board; to provide an improvedadjustable combination of straightedge and protractor; to provide forthe machine an improved central bridge member; to provide an improvedcombination of primary and secondary straightedges; and to provideimproved means for adjustably connecting various parts of the machinewith each other.

Other objects, advantages and features of invention will hereinafterappear.

Referring to the accompanying drawing, which illustrates a preferredembodiment of the invention,

Fig. 1 is a plan view of the machine, parts being broken away tocontract the view.

Fig. 2 is a cross-section on line 22 of Fig. 1.

Fig. 3 is a horizontal sectional detail on line 3-3 of Fig. 2.

Fig. 4 is a fragmental plan of the slide member shown in Fig. 3 havingthrough it a key-hole shaped slot.

Fig. 5 is a fragmental part sectional view on line '55 of Fig. 1.

Referring in detail to the drawing, in the central portion of Fig. 2 isshown an elongated bridge 5 which forms part of a supporting frame andwhich consists of a rigid metal (or metal sub stitute) horizontal platehaving from end to end along one of its long edges a downwardly directedleg-forming flange 6 from the midlength part of which projects outwardlya foot 1, saidfoot con-- sisting of a horizontally outbent ear integralwith said flange 6. Adjacent to its opposite edge the bridge 5 hassecured to its under side a primary straight edge 8 attached by a pairof tapered tongue-amd-groove joints 9 interlocking in a well knownmanner. The outer edge portion of this member 8 has a conventional bevel10, its extreme edge however, being vertical at H. Along the inner sideof said bevel extends an upwardly opening groov I2.

Said groove [2 forms a guide for the downwardly directed flange M of acoupling plate l5 whereby a secondary straightedge I6 is attached to theprimary straightedge 8 in a slidably adjustable manner, the frictionalengagement of said flange [4 with the outer wall of said groove I2maintaining said secondary straightedge I6 in adjusted positions. Thecoupling member l5 overlies the flat top of the inner marginal portionof said secondary straightedge and is secured to it by atongue-and-groove joint ll, like the joints 9 already described. Saidstraightedge l6 has a vertical inner surface I 8 which slidably abutsthe aforesaid vertical edge or surface II of the primary straightedge 8.

A goosenec'k member 22 has a shank 23 attached to an end portion of thesecondary straightedge It by means of another tapered demountable slipjoint 24. .Said gooseneck member carries a sliding foot 25. Saidgooseneck provides an extended clear passage for penciling along thesecondary straightedge l6. Said gooseneck carries a third straightedge26 disposed at a right angle to the straightedge l t, the gooseneckmember having a head 21 joined to the third straightedge by means ofanother conventional demountable joint 28.

At the opposite side of the device the already mentioned foot I isutilized to attach a semicircular protractor plate 30 by means of a pin3! carrying a milled nut 32, thus mounting the protractor for swingableadjustment.

At each side of said protractor the foot 1 carries at its lower edge anoutwardly directed car 33, each of said ears having an index mark 34leading to its inner edge to cooperate with the indicating markings 3-5along the margin of the protractor.

In order to provide for moving the device back and forth across thesurface of a drafting table in a direction extending at a right angle tothe primary straightedge 8, a vertically adjustable wheel or rollershaft 40 is mounted below the bridge 5, a roller 4t having a milled orfriction tread being fixedly fastened to each end of said shaft. Neareach end of th bridge depends therefrom a bearing member 42 for the endportions of said shaft. Said bridge 5 and its supporting frame tiltsupon the shaft 46, as shown in Fig. 2. Over the midlength portion ofsaid shaft the bridge member carries a vertical pin 43 furnished at itslower end with a flattened head 44 through which is a verticallyelongated aperture 45 within the width of which the shaft 40 has a freeworking fit and a Slight vertical play.

Upon the bridge member 5 is mounted a small housing 46 having anapertured top in which is loosely fitted a small cap or closure nut 41which is adjustably screwed onto the aforesaid pin 43 so that saidhousing 46 and related shaft adjusting means is disposed at a pointabout the midlength part of the shaft. Around said pin is loosely coileda compression spring 48 the upper end of which bears against a washer49. Said spring, therefore, acts against abutment means carried by saidpin. Said pin has around it a groove 50 which cooperates with a keyholeslot 5| in a slidably adjustable plate '52 having at one end an upturnedoperating flange 53. The housing 46 is shown having inwardly directedfoot flanges 54 which receive the upwardly directed attaching screws 55.The slide 52 fits workably between said foot flanges and overlies. anaperture in the bridge as large as the widest part of the keyhole slot.Said slide serves releasably to lock the pin 43 in a depressed position.If it is desired to lower the roller 4| from the full line to the dottedline position of Fig. 2 the cap 41 will be screwed outwardly a littlefarther on the threaded portion of the pin 43. Also to lock said rollerin a still farther depressed position the cap 41 can be depressedsufliciently to bring the pins groove 50 into register with the circularpart of the keyhole slot 5| of the slide 52 and then the slide can bemanually shifted to bring the narrow part of its slot into engagementwith the grooved part of the pin, which is connected with the midlengthpart of the shaft 40.

The foot flange of the bridge 5 carries not only the protractor 30 butalso carries a metal strap 60 fixed to said protractor and shaped as abroad inverted U. In the lower part of each end of this strap is abearing aperture for a shaft 6| to each end portion of which is fixed amilled wheel 62 to track on the drafting board or its covering, one ofthese wheels extending through an aperture 63 provided for it in theprotractor. Adjacent to the latter wheel the protractor has secured toits lower face a somewhat compressible chafing member 64.

The strap 60 carries at its inner end a laterally expanded foot 65, thusproviding at each side an ear to receive a screw 66 to attach the strapto the protractor. The protractor pivot pin 3| has at its lower end acountersunk clamping kerfcarrying head 68, and has a milled nut 32screwed onto its upper end portion. Between its ears the aforesaid foot65 has a recess 10 providing a clearance for th aforesaid foot 1, sothat the member 60 may be detached after removing the screws 66. Themachine may be used either with or without having attached to it thestrap 60 and shaft and wheels which it carries.

From Fig. 2 it will be seen that, in regard to the drafting table topsurface 1|, the left portion of the machine (carrying the protractor 30)is in engagement with said surface H, but the right hand portion of themachine (carrying the primary and secondary straightedges) clears thesurface II of the board. The position of the machine shown in this viewresults from the operator pressing downwardly upon the shaft-carryingmember 60. When the machine is thus tilted the wheels 62 engage thedrafting board and enable the operator to move the machine across theboard at a right angle to shaft 6|. When, however, the operator pressesdown down upon the protractor the brake member 64 contacts the board Hand holds the protractor stationary allowing the various straightedgesto be adjusted as desired and used advantageously in drafting. When themachine is tilted in the opposite dimotion the foot member 25 of thegooseneck member contacts the drafting table and also the rollers 4|track upon the board accurately guiding the movement of the machinealong a straight line extending at a right angle to the shaft upon whichsaid rollers are mounted, provided that, at such time the cap 41 and pin43 are held depressed by the plate 52. The brake afiorded by the head 44is at times usable to prevent the machine from rolling off from thedrafting board. The relieving of the pressure of the rollers 4| upon thedrafting board is to provide additional clearance for swiveling orswinging the machine around the protractor. Even when the rollers are intheir raised position they may not entirely clear the board, if theboard has a yielding covering thereover, so that it is still desirableto use the brake.

When the straightedges l6 and 26 are connected to each other by thegooseneck member as shown in Fig. 6, they should be spaced apart asshown at 12, the proper distance to receive between them the pointportion of the draft-sman's pencil.

The secondary straightedge 6 has a. handle l9 attached by screws 20, toslidably operate the flange l4 in the groove l2, and also to lift thestraightedge l6 clear of the table surface II independently of thestraightedge 8 as shown in broken lines in Fig. 2. Owing to the factthat the end portions of the secondary straight edge "5 are shownextending considerably beyond each end of its coupling member I5, it isevident that said secondary straightedge may be so adjusted as toproject beyond the ends of the primary straightedge. When the operatorbrings the handle I9 down toward the housing 46 (for example to thebroken line portion of Fig. 2), there results an equalizing of pressureupon the rollers 4| and a midpositioning of secondary straight edge l6and of the third straightedge 26 to effect a symmetrical drag about thvertical center line of the machine: thereby causing a tendency for themachine to maintain a true line course of travel. In order to pick upthe machine the operator has to bring said housing and handle together.Owing to the guides 42 for the end portions of the shaft 40 havingthrough them vertically elongated apertures through which said shaftpasses, said shaft can be lifted, thus bringing its rollers 4| out ofcontact with the surface of the drafting board, through the action ofspring 48, or said shaft can be manually depressed by the alreadydescribed means to contact said rollers with the board. Said rollers 4|,when in the depressed position, form a fulcrum over which the machine istiltable so that it occupies one position (shown in Fig. 2) when thepair of rollers 62 contact the board and the other position when saidrollers 62 are lifted from the board, the primary straightedge 8engaging the surface of the drafting board in the latter position of themachine. The protractor 30 may be held fixedly stationary on the surfaceof the drafting board while the portion of the machine pivoted to it isangularly adjusted about the pivot 31.

I claim:

1. In a drafting machine, a bridge member, a pair of axially alinedwheels for drafting board travel, an axle member common to said wheels,mounting means for said axle member including bearing means throughwhich said axle passes and an upwardly projecting pin which passesloosely through said bridge member, a spring carried by said bridgemember, means carried by said pin against which said spring abuts toraise said pin and thus lift said axle member normally to maintain saidwheels out of contact with said board, means manually to depress saidpin to bring said wheels into an operative contact with the boardagainst the opposition of said spring, means to releasably lock saidwheels in such contact, a straightedge secured to one side portion ofsaid bridge, and a protractor pivotally attached to its opposite sideportion, said protractor comprising a plate engageable in a flatwisemanner with the surface of a drafting board and having angle indicatinggraduations, said bridg member having foot portions in a cooperativerelation to said graduations.

2. In a drafting machine, a frame, at least two horizontal straightedgescarried by said frame, one of them extending at a right angle to theother, two pairs of axially alined drafting board-engaging wheelscarried by said frame, the axis of one of said pairs of whls extendingat a right angle to that of the other pair, and means for adjusting atleast one of said pairs of wheels to and from operative engagement withthe surface of the drafting board.

3. In a drafting machine, a frame, at least two horizontal straightedgescarried by said frame, one of them extending at a'right angle to theother, two pairs of axially alined drafting board-engaging wheelscarried by said frame. a common shaft to which the wheels of each pairare fixed, and means to vertically adjust at least one of said shafts toadjust therewith the pair of wheels carried by it to and from anoperative engagement with the surface of the drafting board, said shaftadjusting means being mounted upon the frame at a point above themidlength part of the shaft with which it is connected.

4. The subject matter of claim 3, and said frame including a bearingmember for each end portion of said vertically adjustable shaft, each ofsaid bearing members having through it a vertically elongated slotwithin the width of which the shaft has a working fit to allow verticaladjustment of the shaft.

5. In a drafting machine, a frame, at least two horizontal straightedgescarried by said frame, one of them extending at a predetermined angle tothe other, two pairs of axially alined drafting board wheels carried bysaid frame, the axis of one of said pairs of wheels extending at anangle in relation to that of the other pair, a shaft for each of saidpairs of wheels, one wheel being fixedly secured to each end portion ofsaid shafts, bearing means carried by the frame for each end portion ofthe shafts and allowing a slight vertical movement of such end portionsof one of said shafts, a pin connected with the midlength portion ofsaid one shaft and upstanding therefrom, a spring mounted upon the frametendin to raise said pin, said pin being manually depressible againstthe opposition of said spring to depress said one shaft with which thepin is connected and thereby cause the wheels carried by said one shaftto engage th surface of the drafting board, and manually operable meanscarried by the frame releasably to lock said one shaft in its depressedposition.

6. In a drafting machine, a frame, two horizontally extending shaftscarried by said frame, drafting board wheels fixedly secured axially toend portions of said shafts, said shafts extending at substantially aright angle to each other, said frame being tiltable between twopositions in relation to a horizontal drafting board surface whensupported thereon, one pair of said wheels operatively engaging saidsurface in one of said positions and being disengaged therefrom in theother of said positions and the other pair forming a fulcrum for saidtilting, pencil guiding means including a straightedge carried by saidframe, a horizontal foot carried by said frame, a

. protractor pivoted to said foot to swing horizontally, an antislipfoot carried by said protractor, said frame being tiltably supportableas aforesaid to bring said antislip foot into and out of engagement withaforesaid supporting surface, and indicating means carried by theprotractor and an adjacent part of the frame to enable the operator tomake predetermined angular adjustments of said straightedge in relationto the protractor carried by said frame.

'7. In a drafting machine, a frame, a first and second horizontallyextending shaft carried by said frame and extending at substantially aright angle to each other, said second shaft being horizontally spacedaway from said first shaft, drafting board wheels fixedly securedaxially to the end portions of said shafts, said frame being tiltablupon said first shaft between two positions in relation to a horizontaldrafting board surface when supported thereon, the pair of said wheelson said second shaft operatively engaging said surface in one of saidpositions and being disengaged therefrom in the other of said positions,and pencil guiding means consisting of a plurality of straightedgescarried by said frame and angularly related to each other.

8. The subject matter of claim '7, and means manually to adjust into andout of an operative contact with the surface of the drafting board thepair of wheels which cooperates with the aforesaid pair of wheels whichat times are disengaged from the surface of the drafting board.

ARTHUR A. GOERZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,012,340 DuPont Dec. 19, 19111,269,324 Shaver June 11, 1918 1,690,645 Lloyd Nov. 6, 1928 1,746,830Harmon Feb. 11, 1930 FOREIGN PATENTS Number Country Date 58,057 SwedenDec. 30, 1924

